[Qgis-developer] questions on rendering

[Mohammed Rashad]

Hi All,
I am developing tiled vector rendering in OSSIM. I like the Qgis vector
rendering system

point.shp contains 9,99,999 points which are generated by grass for using
v.random and ~27MB in size
roads.shp contains 2,28,068 linestrings and is ~50MB in size

these point.shp and roads.shp data gets rendered in ~10 sec

When I read vector using ogr and parse feature and draw point/linestring my
application taking about 40 sec to render point.shp
and

I am using Qt4 with QPainter not QGraphicsView

How came this time gap?

i see Rtree and pal libs in src/core source code
Does they have any role in rendering?

Does QGIS Rendering uses threading?

How to get a minimal of QGIS code to hack it and build a new vector
rendering because I need it to make it tiled rendering vectors?

How to improve performance in rendering without qgis?
---
Regards,
   Mohammed Rashad K M
   M.S. (By Research) student
   Lab for Spatial Informatics
   Department of CSE
   International Institute of Information Technology
   Hyderabad, India
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